01 - Preheat oven to 350°F (175°C) and grease a 9x13-inch baking dish.
02 - In a large bowl, combine shredded chicken, 1 cup Monterey Jack cheese, 1/2 cup sour cream, green onions, garlic powder, ground cumin, salt, and black pepper. Mix until thoroughly incorporated.
03 - In a saucepan over medium heat, melt unsalted butter. Add all-purpose flour and cook, stirring constantly, for 1–2 minutes until the mixture is bubbling but not browned.
04 - Gradually whisk in chicken broth. Stir continuously until the mixture thickens slightly, about 3 minutes. Remove from heat and whisk in sour cream, diced green chilies, onion powder, and salt until the sauce is smooth.
05 - Spoon the chicken filling evenly onto the center of each flour tortilla. Roll up each tortilla tightly and arrange seam-side down in the prepared baking dish.
06 - Pour the prepared white sauce evenly over the rolled tortillas. Sprinkle the remaining 1 cup Monterey Jack cheese over the top.
07 - Bake uncovered for 25 to 30 minutes until the cheese is melted, edges are bubbling, and the top is lightly golden.
08 - Allow enchiladas to cool slightly. Garnish with chopped cilantro and extra green onions before serving.